With recent advances in digital transmission technology, cable television systems are now capable of providing much more than the traditional analog broadcast video. In implementing enhanced programming, the home communication terminal (“HCT”), otherwise known as the settop box, has become an important computing device for accessing video services and navigating a subscriber through a maze of available services. In addition to supporting traditional analog broadcast video functionality, digital HCTs (or “DHCTs”) now also support an increasing number of two-way digital services such as video-on-demand.
Typically, a DHCT is connected to a cable or satellite television network and includes hardware and software necessary to provide the functionality of the digital television system at the client's site. Preferably, some of the software executed by a DHCT is downloaded and/or updated via the cable television network. Each DHCT also typically includes a processor, communication components and memory, and is connected to a television or other display device, such as a personal computer. While many conventional DHCTs are stand-alone devices that are externally connected to a television, a DHCT and/or its functionality may be integrated into a television or personal computer, as will be appreciated by those of ordinary skill in the art.
There are two complementary phenomena occurring in cable and satellite networks: increasing DHCT performance and increasing network bandwidth. DHCTs with more memory, faster CPUs, etc. are more capable of performing application tasks than their predecessors. Hence, more “powerful” applications can execute on the DHCT client. Second, the latest network technologies enable more bandwidth and throughput of data from the server to the client-effectively allowing more of the application computation and data storage to take place on the server. Thus, there currently exist cable and satellite television networks with older, more resource constrained HCTs and newer, more powerful DHCTs. Additionally, these HCTs exist in networks with differing bandwidth capabilities.
A headend unit comprising one or more servers receives media and data from service providers via a plurality of network interfaces such as satellite, terrestial, telephone, and the internet A headend unit server process receives media and data and then transmits media and data to one or more DHCTs. Since there are various types of DHCTs with differing computing and communication capacities, the server process must convert and output media and data that is limited by the computing and communication capacities of the less-capable DHCTs in the network.
If a network is to contain a mixture of HCTs with different performance capabilities, one of the following must typically be true: 1) the more “powerful” applications are only available to the set of customers with the higher performing DHCTs, 2) multiple versions of the application software, each with different features and functionality, must be provided for each different HCT, or 3) the software and data that is provided to the DHCTs is limited in capability to that of the least common denominator—so that all of the authorized DHCTs are capable of executing the provided software and storing the provided data effectively and efficiently. Each of these has unattractive results for the system operator: unhappy customers, wasted network bandwidth, complex management systems, or wasted DHCT capability and lost revenue. Therefore, there exists a need to take better advantage of DHCTs' computing resources via a more flexible application software architecture that supports and adapts to HCT resource and performance capabilities.
Additionally, as the network bandwidth increases the features and functionality of application software can increase by taking advantage of computation and storage that can be done on the server in the headend. However, networks with different bandwidth and throughput capabilities exist such that an application software vendor might have to develop, distribute, and maintain different versions of the application to execute on the different networks. Thus, there exists a need for an application framework that can adapt to different network capabilities, avoiding the need for multiple versions of the application from having to be developed and deployed. And there is a need to support multiple DHCT types concurrently in a network with an architecture that coordinates media and data processing so that more resource capable DHCTs experience less latency in data access from the network by localizing media and data processing within their confines and so that they can also present users with a more comprehensive and rich media and data presentation.